A federal appeals court halted the execution of Warren Lee Hill to allow more time to consider claims that he's mentally disabled, according to reports.

The 11th U.S. Circuit Court of Appeals issued a last-minute order to halt the execution as Hill, the Georgia man who killed fellow prisoner Joseph Handspike in 1990 with a board studded with nails while he slept, was preparing to receive lethal injection. A panel of the appeals court said in a 2-1 decision that it must further review recent affidavits by doctors who changed their minds about Hill's mental capacity.

Like Us on Facebook

Earlier in the day, the state parole board, the Supreme Court of Georgia and the U.S. Supreme Court had all refused to stop the execution.

"We are greatly relieved that the Eleventh Circuit Court of Appeals has stayed the execution of Warren Hill, a person with mental retardation," said defense attorney Brian Kammer in an email to The Associated Press. "All the doctors who have examined Mr. Hill are unanimous in their diagnosis of mental retardation."

Hill was sentenced to death for the beating death of Handspike, and, at the time, was already serving a life sentence for murder in the 1986 slaying of his girlfriend, Myra Wright, who had been shot 11 times. Nevertheless, he has received support from various activists and from former President Jimmy Carter and his wife Rosalynn.

"Georgia should not violate its own prohibition against executing individuals with serious diminished capacity," said President Carter in a statement.

The state of Georgia passed a law in 1988 prohibiting the execution of mentally disabled death row inmates, while the U.S. Supreme Court in 2002 ruled that the execution of mentally disabled offenders is unconstitutional.

Georgia death penalty defendants have to prove mental disability beyond a reasonable doubt to avoid execution. Hill's lawyers have said that the state's strict standard for proving mental disability is problematic because psychiatric diagnoses are subject to a degree of uncertainty that is essentially impossible to overcome, but nonetheless argue that Hill is mentally disabled and, as a result, shouldn't be executed.

Last week, Hill's lawyers released new affidavits from the three doctors -- two psychiatrists and a psychologist as the Atlanta Journal-Constitution notes -- who examined Hill in 2000 and testified before the court that he was not mentally disabled. They wrote that not only were they rushed in their evaluation at the time and have acquired additional experience since then, but also that there have been scientific developments involving mental disability in the last 12 years.

After reviewing the facts and documents in the case once more, all three wrote that they now believe Hill is mentally disabled. On top of that, all doctors who have examined Hill now agree that Hill is mentally disabled, Hill's team argued.

On the other side, the state maintains that Hill's defense team failed to meet its burden of proving beyond a reasonable doubt that Hill is mentally disabled, also questioning the credibility of the doctors' statements. It said that the doctors did meet with Hill and reviewed facts and documents in 2000, but they haven't seen him since and didn't have significant new information in front of them during their recent review. Given that and their difference in testimony from more than a decade ago, they aren't credible.

The state also cited expert testimony and IQ tests that concluded Hill wasn't at all mentally disabled, but the defense, though, countered by referencing a state court judge's assessment that Hill was and a test that documented his IQ to be around 70. Before trial, the state maintained, Hill wasn't in special education classes and he even served in the Navy, where he received promotions; however, the defense cited expert testimony that it isn't unusual for someone who is even "mildly" mentally disabled to be able to function at a "satisfactory level in an environment as structured as the military."